/* pizza.c -- 使用define定义常量 */

#include <stdio.h>
#define PI 3.14159f

int main(void) 
{
  float area, circum, radius;

  printf("What the radius of your pizza?\n");
  scanf("%f", &radius);

  area = PI * radius * radius;
  circum = 2.0 * PI * radius;

  printf("area = %1.2f, circum = %1.2f\n", area, circum);

  return 0;
}